Dental engine



2 Sheets-Sheet 1.

(No Model.)

JQH00D& $.11. REYNOLDS.

DENTAL ENGINE.

Patented Oct. 29, 1895.

(No Modem M I v 2 she efi ss l let 2. 'J. HOOD 8v S.-'H. REYNOLDS.

DENTAL ENGINE. w 7 No. 548,989. 7 Patented Oct. 29,1895.

UNrTED STAT S PATENT OFFICE.-

JOHN HOOD AND STEPHEN H. REYNOLDS, OF BOSTON, MASSACHUSETTS.

DENTAL ENGINE.

SPECIFICATION forming part of Letters Patent No. 548,989, dated October29, 1895.

Application filed April 20, 1895- Serial No. 546,463. (No model-l T0 atwhom it may concern:

Be it known .that we, JOHN HOOD and STE? PHEN H. REYNOLDS, citizens ofthe United States, residing at Boston, in the county of Suffolk andState of Massachusetts, have invented certain new and usefulImprovements in Dental Engines, of which the following is a full, clear,and exact description, such as will enable those skilled in the art towhich it appertains to make and use the same, reference being had to theaccompanying drawings.

This invention relates to improvements in dental engines of that classin which the main upright consists of an upper and a lower standardhinged together.

It has for its object the construction of such a device whereby theupper standard, by the exertion of a slight force, can be movedrelatively to the lower standard, and which, when free from such force,will assume its normal position,so that an operator can move theoperating-tool to a position more favorable to his work without movingthe whole machine and without'ceasing from the manipulation of theoperating-tool, whereby the upper standard can be moved concentric withthe fiy-wheel, so that the latter and the driving-pulley of theoperating mechanism, carried by the upper standard, will always be thesame distance apart and in substantially the same plane, and whereby thefly-Wheel is Supported independently of the crank-shaft.

The invention consists in the novel construction, combination, andarrangement of parts, such as will be hereinafter fully described,pointed out in the appended claims, and illustrated in the accompanyingdrawings.

In the accompanying drawings, in which similar letters of referencedesignate correspondin g parts, Figure 1 is a side elevation ofa dentalengine embodying the invention. Fig. 2 is an enlarged detail viewshowing, in elevation, the hinged standards, the drivewheel, &c. Fig. 3is a similar view, sh owing the opposite side. Fig. 4 is a horizontalsection on the line 4 4. of Fig. 3. Fig. 5 is a vertical section on theline 5 5 of-Fig. 3, showing the upper standard inclined to one side. Theangle of inclination to the other side is shown by a dotted line. Fig. 6is a similar view,

showing the upper standard in its normal position. Fig. 7 is a detailView showing the connecting ends of the standards disjointed. Fig. 5

8 is a detail view showing the crank-shaft, the sleeve, and theconnecting ends of the standards, the latter being shown in section.Fig. 9 is an enlarged detail view, partly in section, showing thestandards hinged and the wheel and its crankshaft mounted in operativepositions. Fig. 10 is an enlarged detail View showing the arm whichcarries the operative mechanism mounted on the upper standard. Fig. 11is an enlarged detail view, partly in section, showing a portion of thearm and the spring-catch en gagingwith the rack-bar. Fig. 12 is atransverse section on the line 12 12 of Fig. 10. Fig. 13 is aperspective View showing the spring-catch. Fig. 14. is an enlargeddetail view showing the connection between the arm carrying theoperative mechanism and the upper standard. T

Referring to the drawings by letter, A designates the base, of anyconstruction suitable in the premises. To the base is bolted the lowerstandard A; This standard has hinged to its upper end the upper standardB. The hinge B, connecting the standards, in the present instance isformed by bifurcating the upper end of the lower standard andshaping thelower end of the upper standard so that it will register-with thebifurcation. (See Figs. 7, 8, and 9.) The interlocking ends of thestandards are provided with a transverse bearing a, in which isjournaled the sleeve a, which forms the piutle and completes the hinge.In constructing the standards the connecting ends are enlarged, so asnot to be weakened by the loss of the metal cut away 7 in forming thebearing a.

y The opposite sides of the standards those facing the directions inwhich the upper standard moves-are grooved. In these grooves are seatedthe springs S S, which extend along their respective grooves to aconsiderable distance above and below the hinge B. They are respectivelybent at s to pass the knuckle formed by the hinge. The springs arefirmly secured at their lower ends to the lower standard by the clamp s.This clamp is U-shaped,

and its limbs are just far enough apart to firmly press the ends of thesprings'agains't' the standard when it is in position. The ridges ingend of the sleeve a.

s s of the standard are cutaway to allow the passage of the clamp. Thelatter is secured in place by the set-screw .9 (See Fig. 4.)

To permit the obviously-necessary longitudinal movement of the springs,they are held in place in the grooves in the upper standard by thefriction-rollers s .9 These rollers are mounted between the edges oftheir respective grooves and their shafts are journaled in bearingsformed in the projections 5- The springs S S pass under the rollers,which allows a free longitudinal movement. The rollers and the sides ofthe grooves prevent any lateral movement.

The forward movement of the upper standard is limited by the lug aprojecting from the upper end of the lower standard and adapted toengage with a projection of the upper standard when the latter is movedfar enough forward. (See Fig. 7.) The rearward movement of the upperstandard is limited by the lug s projecting from the upper stand-; ard ashort distance from the upper end of the spring S on the rear side, ofthe same. When the upper standard is moved backward far enough, the endof the spring will strike. againt the lug, and as the longitudinal move.ment of the spring is arrested the standard cannot move any farther.This forms an elastic stop, as the spring will give somewhat at the turnwhere it passes the hinge. In case the clamp should not securelyholdthis spring when its upper end comes in contact, with the lug s asecond lug s is provided, and which projects from the lower standard,and against which the lower endof the spring abuts.

The fly-whcel F is journaled on a project- (See Figs. 8 and 9 moreparticularly.) By so wheel its movement will be concentric with that ofthe upper standard. It is provided with a crank-shaft)", which isjournaled in the sleeve. The shaft is secured to the fly-. wheel bymeans of the screws f'f, passing through the flange f projecting fromthe end or head of the shaft. yond the sleeve a on the side opposite tothat on which the wheel is mounted, and has secured on its projectingend the crank-arm f The latter is secured in place by thepin f By thisconstruction each one of the moving surfaces turns on a stationarybearing that is, the wheel is journaled on one end of the sleeve, whichis fixed, the upper standard is journaled on the other end, and thecrank-shaft is journaled within the sleeve.

It is obvious that the sleeve could be done away with to some extent andthe crank-shaft journaled in the bearing formed in the standards andform thereby the pintleof the hinge connecting the two standards.

It is also obvious that the results wouldnot be so good, for the wheelwould have no independent bearing and its whole strain would have to beborne by the crank-shaft, and also the latter would be journaled in a.bearing mounting the The latter projects beformed of two independentbodiesnamely, the bearings formed in the interlocking ends of thestandards, one of which is movable. It can be readily seen that suchamechanism would be objectionable, as the wearing parts would soon cuteach other away, owing to the uneven surfaces and the irregulardistribution of the strains. This is overcome to a great extent by theconstruction in the present instance, which gives each moving surface astationary and a single surface to bear upon, and which distributes thestrain much more evenly.

Means are provided whereby the several wearing-surfaces above mentionedare lubricated. Apassage It leads through one of the bifurcations of thelower standard to the sleeve a, where it registers with a. passage 72, 5leading through the sleeve to thecrank-shaft. (SeeFig. 9 moreparticularly.) Oil on being introduced into thepassage It will pass tothe crank-shaft, and there distribute itself over the wearing-surface 71On its passage to the shaft some of it will enter between the sleeve1and the surface of the upper standard. As the movement of the. standardis very limited, very little oil will be required to lubricate the 1wearing-surface of the same. After reaching the crank-shaft much of theoil will collect in the annular recess 7r, formed in the crankshaft,from which it will feed through the j passage. 7L4" to theann ularrecess 7L5, formed in the outer periphery of the sleeve, from whichrecess it will be. distributed to the wearingsurfaces of the wheel andthe sleeve. From the recess h the oil will also be fed to thewearing-surface, h? of the crank-shaft. By this construction thelubrication of the several wearing parts is much simplified.

The crank-arm is connected with the free end of the treadle by theconnecting-rod f The lower end: of the latter is extended be.-

low the pointwhere it is pivoted to the treadle, and its extreme end isconnected bya spring f to the treadle, which serves to keep the flywheeloff dead-center.

The telescopic extension K is secured upon the upper end of the standard13, and it has swiveled on its upper end the arm K, carrying theoperating-tool and the mechanism for j driving the latter. Theconnection between of the telescopic extension and allows the arm K tobe turned horizontally, and the arm K is a hinged joint. that allows avertical movement of the said arm K. This joint consists I of the arms10 which project from the upper end of the rod 70 outwardly in oppositedirections and then upwardly. To the ends of these are respectivelypivoted theendsof the arms k is". The latter arms project outwardly inopposite directions from the lug 76 and. then rearwardly to their pointsof connection with the first-mentioned arms. It is to. be observed thatthe arms 70 70 are curved 1 so. as to allow a free passage of the beltto the driving-pulley. The arms 75470 are angular IiO the rod 70 whichextends into the upper end sary resilience.

to give the proper clearance of the moving parts as the arm K is raisedor lowered. The arm K is cylindrical and has mounted therein thedriving-shaft k", which extends from the rear end of the arm and hasmounted thereon the pulley 7c". The latter is so mounted as to allow thedriving-shaft to move in and out as the helix to which it is connectedshortens or lengthens. To the inside of the arms 10 10 are mountedfriction-rollers, against which the pulley k bears when carried inwardlyby the shaft. (See in dotted lines, Fig. 10.)

The adjusting-brace N is hinged to the upper end of the rod 10 betweenthe diverging arms k 70 It serves to support the arm K in its verticaladjustment. The free end of the brace has pivoted thereto the rack-barn. The latter moves in the guide it, attached to the under side of thearm K. A spring-catch N is provided which is adapted to engage with therack-bar. (See Fig. 10.) The catch is substantially cruciform in shape,and it is mounted in a slot formed in the under side of the arm K. Theshank n of the catch is secured to the inner face of the cylindrical armby the spring 02 which gives it the neces- The arms n n of the catch arecurved so as to conform with the transverse shape of the arm and serveto hold the catch in place. The extension a is bent so as to readilyengage with the rack-bar H. To the end of one of the arms n n thefingerpiece at is attached. The latter curves beneath the rack-bar andforms a means whereby the catch can be readily disengaged from therack-bar and thereby allow the arm K to be lowered. It offers noopposition to the elevation of the arm.

It is to be observed that the standards A and B have offsets at so Thisallows the fly-wheel and the driving-pulleyto be mounted insubstantially the same vertical plane.

It is obvious that the construction hereinbefore described can bedeparted from to-a considerable extent without departing from the spiritof the invention.

Having thus described our invention, what we claim, and desire to secureby Letters Patent, is as follows:

1. In a dental engine, the combination of the lower standard, the upperstandard hinged thereto, the springs placed on opposite sides of thesaid standards to normally hold the same in substantially the samestraight line, the mechanism securely fastening the springs to one ofthe standards, and the mechanism holding the springs in close contactwith the other of the said standards and at the same time allowing freelongitudinal movement of the springs on the latter standard,substantially as described.

2. In a dental engine, the combination of the lower standard, the upperstandard hinged thereto, the springs placed on opposite sides of thesaid standards to normally hold the same in substantially the samestraight line, the clamp securing the springs to one of the standards,and the mechanism holding the springs in close contact with the other ofthe said standards and at the same time allowing a free longitudinalmovement of the springs on the latter standard, substantially asdescribed.

3. In a dental engine, the combination of the lower standard, the upperstandard hinged thereto, the springs placed on opposite sides of thesaid standards to normally hold the same in substantially the samestraight line, the mechanism securing the springs to one of the saidstandards, and the anti-friction rollers holding the springs in closecontact with the other of the said standards and at the same timeallowinga free longitudinal movement of the springs on the latterstandard, substantially as described.

4. In a dental engine, the combination of the lower standard, the upperstandard hinged thereto, the springs placed on opposite sides of thesaid standards to normally hold the same in substantially the samestraight line, the clamp securing the springs to one of the saidstandards, and the anti-friction rollers holding the springs in closecontact with the other of the said standards and at the same timeallowing a free longitudinal movement of the springs on the latterstandard, substantially as described.

5 In a dental engine, the combination of the lower and upper standardshinged together, the sleeve forming the pintle for the said connection,the fly-wheel journaled on the said sleeve, and the crank-shaft securedto the flywheel and journaled in the said sleeve, substantially asdescribed.

In testimony whereof we aiiix our signatures in the presence of twowitnesses.

JOHN HOOD. STEPHEN H. REYNOLDS. Witnesses:

EUGENE H. M00121), GEO. L. RIDLEY.

